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[How to] Remove the ABS from a ST185

Fri Mar 27, 2009 4:10 am

The old post regarding this subject put up by Silence has broken pics & a lot of people has asked for a write-up w/part numbers, so I decided to offer a new how to article for those interested in removing the ABS from their ST185.

*** Disclaimer *** This is simply a guide showing how I removed the ABS from my car. I am not responsible for any damage or anything that may happen to you or anyone else in your car or any damage to your car itself if you choose to follow what I have written here.

It goes without saying this is a project best done with the engine/tranny removed. You can do it with the motor in there, but you're going to make it a bigger pain than it already is to do.

Be sure to have lots of blue paper towels or just plain work towels & a bucket to catch brake fluid before you get started.

First things first, you will not need to touch any of the hardlines going to the rear of the car.
They are the same on all 90-93 Celica models.

Also, the hard line that goes to the driver's side fender/wheel well will stay & not be replaced.

Here are all the lines physically in the car going along the firewall to the passenger side to the ABS unit which will be referred to as the brick from now on.


Let's start with removing the old ABS lines. You are going to want to get as much brake fluid out of your reservior as you can - I use a syringe to suck it out + it gets a lot of the dirty pieces that are most likely in there thanks to the previous owner of the car & their lack of maintenance.
When you remove the lines there will be brake fluid still in there no matter how dry you think the system is. Brake fluid will eat paint if you let it sit on there so if you get any fluid on your paint wipe it up immediately!

Remove all the lines going towards the passenger side that are coming off the proportioning valve or p-valve.

The p-valve is here - circled in green.

You can see all the lines coming off it. You will be removing the p-valve also.
You will have to remove the clutch line that goes to the p-valve.

You will also be removing the 2-way valve which is right on the brake booster - it's circled in yellow.


6 lines go to and from the ABS brick.
1 Line goes to the pass side wheel well from the brick & you will most likely have to remove your wheel to get it off. It goes to your soft (either rubber or SS) brake lines which go to the caliper.
You may have to unbolt some power steering lines to get to the ABS lines to remove them. Same thing goes for PS fluid - clean it up immediately.
The 5 other lines snake around & go to the ABS brick. There is an additional P-Valve that is on the back side of the ABS brick.. you have to take off the 6 lines that go to the P-Valve and the brick itself.


1 other line comes directly off the master cylinder & goes to the 2-way -- this will also be replaced.
Again, leave the line going to the driver's side.

Now that all the lines are out you have the ABS brick left.
In order to remove this heavy chunk of metal you are going to have to have your pass side wheel off, take off the plastic fender liner part way, get under the car & remove the windshield washer reservoir. There are several bolts holding it in underneath & its a pain to remove. The ABS brick won't come loose without taking out the windshield washer reservoir though so you have to do it. Make sure this is empty too otherwise you will get a shower when you unhook the line going to the sprayers.

Once you get all the bolts holding in the ABS brick removed, you will have some left over bits coming from the harness that went to the ABS and the lines that were for testing and for the ABS relay that was mounted to the Radiator.
You can either cut them off & nicely tape the wires back to the harness or tuck them away somewhere - your choice.
You'll also have to figure out a new way to mount your small fuse box there if you still have it.
Also, there is a small bracket that holds down the hard power steering lines... you can cut that off of the ABS Brick bracket, and use that by itself to keep the PS lines secure.

The Non-ABS lines you will need are shown in this drawing below. The lines circled in red are discontinued & can no longer be ordered brand new from Toyota. They are also in red font below. You are basically going to need to get 4 lines, a P-Valve & 3-way valve.


Lines No longer available from Toyota:
47314-20360 Line passenger to P-valve
47313-20480 Line P-valve to 3-way
47311-20710 Line P-valve to master cylinder
47315-20490 Line driver to 3-way (same on both ABS & w/o ABS, no need to remove or replace)

Still available from Toyota, low stock:
47312-20190 Line master cyl to 3-way
47150-20140 AWD Non-ABS Proportioning valve
90413-10182 3-way

These brake lines can be sourced from any 90-93 ST, GT or GT-S model which did not have ABS.
ST's are the most common to find & most didn't have ABS so they are your best bet in a junkyard.
When removing the lines be careful not to mess up the ends where you remove the nuts otherwise you will have leaking problems down the road.
Of course, you can make the lines yourself if you know how to flare lines.

Regarding the P-valve:
You will notice when you removed your ABS brick there is a P-valve on it.
It appears to be the same P-Valve as the Non ABS AWD P-valve.
Use that P-valve at your own risk as it is as old as your car.
Some people use P-valves from Non ABS ST's and are just fine with it.
I believe that it will change your brake bias more towards the front since ST's typically have drums in the rear.
The P-valve found in Non-ABS Camry Alltrac's are the same part number as the Non ABS Alltrac P-valve.
A brand new Non ABS AWD P-valve does run ~$158 USD so if you are on a budget & just grab a P-valve from the FWD Celica you stripped just be aware you may notice a difference in brake bias if you are that in tune with your car.

3-way valves can be had off junkyard Celica's or can be bought brand new, again your choice depending on budget & your own personal safety concerns.

When you replace the lines you will find the clips are different. You will only have 1 line going to the passenger side so you will need to make sure you get the clips in the junkyard along with the lines so it will look like your car was never equipped with ABS.

Start by putting in your new P-valve & attach all the non ABS lines to it, re-attach your clutch line & install your 3-way & arrange the lines to it as well. Install the line that goes from the 3-way to the master cylinder also.
With the correct brackets, you should have something looking like this:


Put your windshield washer reservoir back in, button everything back up & fill with brake fluid. Check your connections for any leaks & tighten if necessary. Bleed the system.

When you start the car you'll notice the ABS light on in the dash.
This is the ABS ECU flipping out b/c it can't locate any of the ABS stuff you just removed.
There are 2 ways to take care of the ABS idiot light.
1 way is you can simply remove the light bulb behind the cluster.
The other way is removing the ABS ECU. It's located on the passenger side in the backseat area. You will have to remove the backseat bottom & top in order to remove the plastic trim where the speaker is located. Once you get that trim removed, you'll see the speaker itself & a big plastic box.
Remove the speaker + box. Now, you'll see some wire loom & 3 nuts.

The 3 nuts are where the ABS ECU is located. You can see in the pics below where it is looking up into the rear quarter area. Disconnect the plugs, remove the ECU & voila! no more ABS idiot light.



When you're done, your engine bay should look like this - less cluttered & look like the factory option was never there on your car.


If you get all your parts from a junkyard this is a very inexpensive project which will clean up your engine bay, drop a few pounds off the front & allow you better control over braking in certain weather situations namely snow/ice.
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Tue Mar 31, 2009 11:18 pm

Has anyone converted to no ABS and had any type of issue with the pedal being spongy during engine operation. Replaced the lines, P-valve and t-fitting from a non ABS celica st, 92-93 body. The problem is that when the vehicle is running the pedal will almost go to the floor unless you pump the pedal quickly, the pedal will come back and be very firm, it's as though the brake fluid is returning back to the M/C and the pads are pulling away from the rotor just a bit, then when i depress the pedal again the fluid would have to push the pads back against the rotor, that is what it feels like. Is there a pressure relief valve in the system that i would have removed when performing the swap that retains certain pressure on the system whe your foot is lifted off the pedal? just curious if anyone has had this problem.


Tue Mar 31, 2009 11:27 pm

that almost sounds like a lot of air in the system to me -- might want to try to bleed your brakes again.

Re: [How to] Remove the ABS from a ST185

Tue Jan 12, 2010 7:06 pm

Finished mine up yesterday, with my motor in. It wasnt that bad, had a few snags but nothing I couldnt handle. The brakes feel alot more direct now, I guess the fluid going through like 10 feet of line would make them softer. Good write up bud.

Re: [How to] Remove the ABS from a ST185

Tue Jan 12, 2010 7:17 pm

Be careful who you call "bud" As she is my wife.. 8)

I am glad that this helped someone..

Extra note:
Any extra connectors where the ABS unit was near the windshield washer unit can be tucked or clipped, as they are no longer needed.

Re: [How to] Remove the ABS from a ST185

Tue Jan 12, 2010 7:27 pm

Ill just say Rip then :D yeah i snipped all the extras

Re: [How to] Remove the ABS from a ST185

Tue Feb 02, 2010 3:46 pm

I also just finished this with the motor in.
and this thread helped me out with the whole thing.
from taking it apart to getting to the junk yard to reinstalling.
I bought the one line and the T new from toyota. then used the p-valve from my cars abs brick, and just took the other three lines and brackets from the junk yard.
got them for $10, everything for less than $35.

So even with the motor in it was straight forward, a little tight in areas but def. doable without a lot of headaches.
One recommendation I have is, when installing the new p-valve, thread in the line that goes to the bottom of it before getting the rest connected or else you will be cursing alot! then connect the rear lines and the one to the master. also it is easier to disconnect the ps lines and move them around to have enough room to twist the new passenger caliper line in without bending it.

One last note, the p-valve from the abs brick is the same part # as far as I can tell and will not change your bias. and I think it is better to use yours than one that was sitting out in a junk yard. just my opinion, plus it was in your car and you know the general condition of it. This is of course if you dont buy a new one.

brake feel is greatly improved, but I also put in goodridge lines at the same time so Im sure that helped too. A worthwhile mod I think.

Re: [How to] Remove the ABS from a ST185

Mon Mar 08, 2010 3:13 am

Thank you, so, so much.

Doing this as soon as I can.


Re: [How to] Remove the ABS from a ST185

Sun Mar 21, 2010 10:41 pm

did any of the gt fours come with no abs? my 1991 gt four has none...?

Re: [How to] Remove the ABS from a ST185

Sun Mar 21, 2010 10:51 pm

My guess is your's was removed. Anything else aftermarket/modified on it? I think all gt-fours had it, but I'm not an expert.


Re: [How to] Remove the ABS from a ST185

Mon Mar 22, 2010 12:55 am

ABS was an option for 90-91 US models.
I have seen some CS/RC models without ABS, no system 10 & no sunroof.
All US '93 models came with ABS, leather, sunroof & system 10.
I'm unsure of '92 models - most seem to have ABS but I have seen only one without a sunroof.

Glad this write-up has helped people here also :)

Re: [How to] Remove the ABS from a ST185

Mon Mar 22, 2010 11:09 am

why would you want to remove the ABS ?

Re: [How to] Remove the ABS from a ST185

Mon Mar 22, 2010 12:04 pm

UndaGrwnD wrote:why would you want to remove the ABS ?

In our case, we wanted to remove the ABS because:
a. It was not working properly
b. Because it was not working right, it was causing the rest of the brakes to perform poorly.
c. It is an eyesore and took up a lot of room inside the engine bay
d. It has NEVER worked (At least not on our car) :shoots:

It was not exactly cost effective to "repair" it.. it made much more sense to just go ahead and rip it out.
Makes things A LOT simpler.. and on an All-Trac, you need as much "simple" as you can get.
Last edited by justjoe on Wed Mar 24, 2010 2:57 pm, edited 1 time in total.

Re: [How to] Remove the ABS from a ST185

Wed Mar 24, 2010 9:36 am

oh oke.

i think ABS is important...its much better braking right..?

Re: [How to] Remove the ABS from a ST185

Wed Mar 24, 2010 6:55 pm

it can depend on a lot on where you live, for example on snowy roads ABS can be an advantage.

personally i prefer my own braking abilities to that of an antiquated ABS system that never worked properly in the first place along with upgraded 4 pot calipers up front, 2 pot calipers in rear to do all the work.

of course it cannot be said enough that brakes & all their components are something that can save your life & the lives of others.

this is simply a write-up for those who wish to remove their ABS.
if you want to start a discussion of the benefits of ABS vs. No ABS then please start a thread in Club Chat - thanks!
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